The present invention relates to an apparatus for attaching a suture to a surgical needle of eyeless type.
Hitherto, as shown in FIG. 1, when a suture 3 is to be attached to a surgical needle 1 of eyeless type, an operator has the suture 3 with his one hand, and the surgical needle 1 with his other hand. The operator inserts an end of the suture 3 into a bore 2 which is formed in a proximal end of the surgical needle 1 and which extends along an axis of the surgical needle 1. The surgical needle 1 having the suture 3 inserted into the bore 2 is then set between a pair of lower and upper staking dies 5 and 6 as shown in FIG. 2. The upper staking die 6 is moved toward the lower staking die 5 to stake the proximal end of the surgical needle 1, thereby attaching the suture 3 to the surgical needle 1.
The above-described attaching method has the following problems. First, since the surgical needle 1 and the suture 3 are extremely fine in diameter, considerable skill is required for the operation of insertion of the suture 3 into the bore 2 of the surgical needle 1. In addition, the inserting operation overworks the operator's eyes, making it difficult to continue the inserting operation for a long period of time.
Secondly, since the axial position of the surgical needle 1 is measured with the eye, it is difficult to position the surgical needle 1 correctly. Specifically, as indicated by the phantom lines in FIG. 2, staking might be carried out with the proximal end of the surgical needle 1 protruding considerably from the staking dies 5 and 6, resulting in defective products.
In order to dissolve the above second problem, an apparatus has been developed as shown in FIG. 3, which is provided with a stopper 7. The stopper 7 is arranged beside the lower staking die 5, and has an upper end protruding from the lower staking die 5. The protruding height of the upper end of the stopper 7 is less than a thickness of a peripheral wall of the surgical needle 1 surrounding the bore 2, in order not to prevent insertion of the suture 3. The proximal end face of the surgical needle 1 is abutted against the stopper 7 so that the surgical needle 1 is positioned axially. However, the following problem might occur in the apparatus shown in FIG. 3. That is, since the height of the upper end of the stopper 7 protruding from the lower staking die 5 is very small, the proximal end of the surgical needle 1 might run on to the stopper 7. If the surgical needle 1 is staked by the staking dies 5 and 6 with the proximal end of the surgical needle 1 running on to the stopper 7, a staking defect would occur as shown in FIG. 4.
The apparatuses illustrated in FIGS. 2 through are disclosed, for example, in Japanese Patent Publication Nos. 56-43420 and 57-56412, Japanese Utility Model Publication Nos. 57-10646, 61-88564 and 62-4345, U.S. Pat. No. 4,306,443 corresponding to the abovementioned Japanese Patent Publication No. 57-56412, U.S. Pat. No. 4,722,384 issued on Feb. 2, 1988, and the like. The above-noted patents have all been filed in the name of the assignee of this application.